Freight Wagon Mass Reduction using Parametric Optimisation

Abstract

Advancements in the railroad industry are driven by the need to have faster, lighter trains, while adhering to rigorous safety standards. Implementation of FEM analysis in wagon design enables engineers to examine every aspect of wagon construction in virtual space and to affirm that all safety requirements are satisfied before the first prototype is made. Using FEM, engineers can identify areas of stress concentration in wagon construction, and if those calculated stresses exceed maximum permissible stress, they need to modify the design of the wagon until safety factor is reached. Also, finite element results can be used to identify over dimensioned part of construction which unnecessarily increase the weight and cost of wagon. Every change in design requires entire wagon to be re-analyzed for every prescribed load condition, which can become a very tedious endeavour. Implementation of the parametric optimization in wagon design is an advanced approach which automates the process of changing numerous plate thicknesses simultaneously while keeping maximum stresses within safety limits. If the initial design satisfies all safety requirements this procedure helps engineers to further improve wagon design, while if the initial design is flawed, parametric optimization can be used to search for a solution that meets all safety conditions. This technique is used to enhance design of freight wagon which will be used for transportation of granular materials. Optimization results identified several plates which thickness can be reduced, while overall wagon design is proven to be very well dimensioned.